Malignant neoplasm of extrahepatic bile duct

This code signifies a cancerous tumor originating in the bile ducts located outside the liver. These ducts are responsible for transporting bile from the liver and gallbladder to the small intestine. The malignancy is confined to the extrahepatic portions of this biliary tree.

Apply this code when documentation explicitly states a primary malignant neoplasm of an extrahepatic bile duct, such as the common bile duct, cystic duct, or hepatic ducts outside the liver. Supporting documentation typically includes pathology reports confirming malignancy and imaging studies identifying the tumor's location.

• Differentiate from intrahepatic bile duct malignancies (C22.1) or neoplasms of the ampulla of Vater (C24.1).
• Ensure the documentation specifies "extrahepatic" to avoid miscoding.
• Sequence as the primary diagnosis when this is the reason for the encounter, followed by any associated conditions or complications.